SAN DIEGO — Police suspect the same man was involved in a string of robberies, including at a Chevron and Jack in the Box, overnight in a section of San Diego County, authorities said Saturday.

The first incident was a failed robbery attempt that happened Friday at a Rite Aid in Carmel Mountain. It was reported to police around 9:40 p.m. at 11845 Carmel Mountain Road.

Officer Robert Heims of the San Diego Police Department said the man entered the store and walked to the counter, demanding money from the employee. With the employee unable to open the register, the suspected robber got upset and walked out of the store, heading northeast through the parking lot.

Later that night around 11:27 p.m., police believe the same man entered a Chevron gas station at 9936 Mercy Road in Mira Mesa and demanded money from the employee. According to Heims, he managed to take the cash and left the store, walking westbound on Mercy Rd toward Black Mountain Rd.

Around two hours later, a robbery was reported around 1:32 a.m. in the 6900 block at the Jack in the Box in Miramar. Police said the man suspected in the other two robberies walked up to the drive-thru window and demanded money from the employee. The employee complied, giving the man the money from the register and walking away westbound on Miramar Road.

The SDPD said robbery detectives were investigating all three incidents.