The Tampa Police Department needs your help catching a killer. Investigators released new video of a murder victim, 25-year-old Dontae Lampkins. It shows Lampkins as he got on and off a HART bus on January 24, 2017. It’s one of the last times he was seen alive.

Investigators say he was likely going to meet his killer who he connected with through an online dating app.

Two days later, construction workers found the 25-year-old dead in an alley near Hillsborough Avenue and Nebraska Street.

Lampkins is the third gay man murdered just a few weeks apart in the Seminole Heights area.

Lampkins’ sister, Devada Carlton, tells 10News that he didn’t deserve to die and be left in the secluded alley between E. Mohawk and Comanche Avenues.

Nearly 2 months after his brutal murder, his family and police are desperate for justice.

“I always told him, ‘Don't leave without telling us where you're going’. He would just be like, ‘Okay, I'm going out, and I'll be back,’” says Carlton.

Carlton doesn't know who her brother had been going to meet. Police say apparently a man he met through an online dating app. It turned out to be a deadly ride. Lampkins got off this bus and never made it home or to work the next day. His body was found a couple blocks from the bus stop in the alley.

“We're asking everyone to please be careful,” says Tampa Police Department Captain Ruben Delgado.

Capt. Delgado won’t say what dating app the victim had been using, but insists it's a warning for everyone about meeting up with strangers.

Nearby workers reported hearing gunshots. A witness helped police come up with a sketch of a possible suspect.

Investigators hope the new video triggers some tips either from someone who saw Lampkins moments before his murder or other online daters.

“That's why it's imperative, when you do participate in a dating site, that you do meet in public places, you don't get lured into an area that is somewhere not safe,” says Capt. Delgado.

Neighbors tell 10News that they know bad parts border the area. Some are concerned this makes three gay men murdered in Seminole Heights in December and January. Police insist the killings aren't connected.

Police say Keith Davis has been arrested for the murder of William McGoff. Investigators say Davis killed McGoff in his Chariton Avenue home and stole his car on December 11th.

Investigators say they’re closing in on suspects in the January 14th beating death of William Denham near N. 15th and E. Elm streets in Seminole Heights.

“One of them we solved. The other one we're pretty confident we have the offenders identified. Completely separate, unrelated events,” says Capt. Delgado.

Lampkins family wants that closure.

“It's like, why? There wasn't no reason. What did he ever do to you? We're going to get justice, one way or another,” says Carlton.

Crime Stoppers of Tampa Bay is offering a reward of up to $3,000 for information that leads to the identification and arrest of the suspect in this case. Anyone with any information regarding this case and who wants to be eligible for a cash reward is asked to call Crime Stoppers at 1-800-873-TIPS (8477), report anonymously online or send a mobile tip using the P3 Tips mobile application, which is a free download for iPhones, iPads, and Droids.

The public is asked to help catch Lampkins’ killer by sharing the new video. You can find it on the 10News Facebook page.