Updated

Two shootings at two entertainment venues in Orlando, Fla. over the weekend left 50 victims dead and some wondering what more, if anything, can be done to effectively secure nightclubs and theaters.

Forty-nine victims lost their lives inside the Pulse night club early Sunday morning in the worst mass shooting in U.S. history just two days after pop star Christina Grimmie was gunned down outside the city’s The Plaza Live at an autograph signing after a concert.

Florida-based private investigator Patricia E. D’Orsa-Dijamco told FOX411 that Grimmie’s murder may have been avoided if security measures used to screen people before they entered the club were employed outside the venue as well.

“Perhaps if security was present and fans were being checked in advance of meeting with Christina, the tragedy may have been prevented,” D’Orsa-Dijamco said.

According to Orlando Police Chief John Mina, Grimmie was approached by the gunman, identified as 27-year-old Kevin Loibl of St. Petersburg, Fla., while she was hosting a meet-and-greet for her fans outside the venue. Loibl was reportedly armed with two handguns, two loaded magazines, and a hunting knife.

There were two unarmed security guards at The Plaza Live and they checked bags and purses for contraband before people entered the concert, but the shooter waited to approach Grimmie until after the concert, when the singer was signing autographs around 10 p.m. Loibl walked directly up to Grimmie and shot her point blank before her brother, Marcus, tackled the shooter to the ground. The shooter shot and killed himself during the fight with Marcus. Grimmie was rushed to the hospital but died from her wounds.

The Plaza Live’s security policies listed on its website state in part: “Patrons and their belongings may be searched by Plaza Live staff using both contact and non-contact methods. Without proper authorization, Patrons are not permitted to possess the follow items while on Plaza Live property at any time; Firearms/ Concealed Weapons."

Former undercover DEA agent Michael Levine said preventing murders like Grimmie’s is very complicated.

"Overall prevention of the killing of public or famous figures is impossible in a free society," Levine said. "The opportunities to commit this stalker type of homicide in the case of Grimmie can be limited by the following -- mental health certification for all gun buyers and security personnel employed by medium to large venue gathering places, furnished body armor, less than lethal force devices, and training in all areas associated with physical protection.”

The Plaza Live is not responding to press requests at the moment, saying in a statement posted on its website: “We are closely working with The Orlando Police Department on this active law enforcement investigation and therefore necessarily defer specific questions to OPD's Public Information Officer.”

FOX411 reached out to the Orlando Police Department's PIO but did not receive comment, most likley because they are dealing with an even more heinous situation with the mass shooting at the Pulse nightclub.

Omar Mateen pledged his allegiance to ISIS during a 911 call after he began his shooting spree around 2 a.m. on Sunday morning. Mateen, 29, approached Pulse, a gay nightclub, with an AR-15 and a Glock, and got into a gunfight with an armed security guard. Mateen got past him and entered the building. The officer was joined by two additional officers who also engaged Mateen. Mateen retreated further into the nightclub and took patrons hostage. He held his hostages until an armored SWAT vehicle created a hole in the wall which the shooter walked through firing at officers. He was shot dead, but only after he killed 49 people and injured 53 others.

Mike Baker, a former CIA agent and President of Diligence LLC, a private intelligence and security firm, said shooters who plan ahead can take advantage of security loopholes.

“Timing and location -- meaning how the shooter chose this target and when to attack -- shows pre-planning and some level of knowledge, possibly surveillance or research into the target site. He appears to have known the closing time of the club,” said Baker. “Perhaps he chose it for a reason or reasons related to maximizing the number of victims and the ability to get past security.”

FOX411 called Pulse’s rep to see what security was provided at the venue during the night of the attack but did not get a response.

The owner of Pulse, Barabara Poma, posted a statement on the venue’s website: “Like everyone in the country, I am devastated about the horrific events that have taken place today. Pulse, and the men and women who work there, have been my family for nearly 15 years. From the beginning, Pulse has served as a place of love and acceptance for the LGBTQ community. I want to express my profound sadness and condolences to all who have lost loved ones. Please know that my grief and heart are with you.”